DESCRIPTION: (Adapted from applicants abstract) The goal of this study is to conduct a randomized, controlled clinical trial comparing back school, back strength and flexibility exercise interventions, and a no- treatment control group for prevention of work-related back injury and associated costs of back injury in a group of firefighters at risk for back injury. Expenditures for medical care, workers' compensation and lost work time resulting from back injury exceed 16 billion dollars per year. Back injury is the leading cause of job-related injury retirements among firefighters. A systematic controlled investigation is needed to compare worksite educational/exercise approaches which may be of benefit in occupational back injury prevention. Results of this study will guide occupational health nurses and other safety and health personnel in selecting back school or exercise interventions for prevention of back injuries among firefighters. Subjects will be 180 career firefighters from 21 fire stations who are employed by a large municipal fire department in the Southeast and who volunteer to participate in the study. A three group repeated measures design will be used in which fire stations will be randomly assigned to a back school group (education and exercise), back strength and flexibility exercise group, or a no-treatment control group. Outcome variables of back knowledge and trunk performance, measured by the Isostation B-200 computerized back testing equipment and a battery of clinical tests (sit and reach, modified Schoeber, curl-ups, and arch-ups) will be assessed prior to the intervention, at the end of the twelve week intervention, and at six months post-intervention. Incidence of work-related back injuries, medical costs, lost time, and lost-time costs will be compared among groups at eighteen months post-intervention. General linear models methodology will be utilized to determine if post-test differences in trunk performance, back knowledge, incidence of back injury, medical costs, lost time, and lost-time costs exist between the study groups. Results are expected to indicate which of the worksite education/exercise approaches is more efficacious in improving back strength and flexibility and controlling occupational back injury costs among firefighters.